[interpreter] Fix debug stepping for generators.

test/mjsunit/es6/debug-stepin-generators.js

Index: test/mjsunit/es6/debug-stepin-generators.js
diff --git a/test/mjsunit/es6/debug-stepin-generators.js b/test/mjsunit/es6/debug-stepin-generators.js
index 081dfb706333e007c120c5d3988d3b87fe68ff27..6e548b480a76c4b5a177a7af811295c4db8f7907 100644
--- a/test/mjsunit/es6/debug-stepin-generators.js
+++ b/test/mjsunit/es6/debug-stepin-generators.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --ignition-generators

[rmcilroy, 2016/06/09 10:50:18]

Do we want to only test --ignition-generators with this test? Michi made the
good point yesterday that we should probably just remove the
--ignition-generators flag and use ignition generators if --ignition is set
(otherwise FCG currently) - this would mean that all generator mjsunit tests
would end up being run with ignition generators in the ignition testing variant.
WDYT (as a followup CL)?

 
 Debug = debug.Debug
 var exception = null;